-dpi 100 forces square pixels even on 16:9 display with 4:3 pixel resolution

Bug #151310 reported by laga
4
Affects Status Importance Assigned to Milestone
Mythbuntu
Fix Released
High
Nick Fox

Bug Description

Title says it all.

Fonts were unreadable on my TV because GDM was not set up to use -dpi 100. Since we already fiddle with GDM config when we configure auto login, it#d be cool to add -dpi 100 in there. I think that was also done in ubuntu-mythtv-frontend.

I've remedied this problem for now by adding this in gdm.conf-custom:
[server-Standard]
name=Standard server
command=/usr/bin/X -br -audit 0 -dpi 100
flexible=true

Revision history for this message
Mario Limonciello (superm1) wrote : Re: [Bug 151310] -dpi 100 missing from X command line in gdm in Beta 1

Dude,

Does this work? You don't need to put in the DPI anywhere else like Display
Size or anything like that when you do this? That'd be awesome!.

On 10/10/07, Michael Haas <email address hidden> wrote:
>
> Public bug reported:
>
> Title says it all.
>
> Fonts were unreadable on my TV because GDM was not set up to use -dpi
> 100. Since we already fiddle with GDM config when we configure auto
> login, it#d be cool to add -dpi 100 in there. I think that was also done
> in ubuntu-mythtv-frontend.
>
> I've remedied this problem for now by adding this in gdm.conf-custom:
> [server-Standard]
> name=Standard server
> command=/usr/bin/X -br -audit 0 -dpi 100
> flexible=true
>
> ** Affects: mythbuntu
> Importance: Undecided
> Status: New
>
> --
> -dpi 100 missing from X command line in gdm in Beta 1
> https://bugs.launchpad.net/bugs/151310
> You received this bug notification because you are a member of
> Mythbuntu, which is the bug contact for Mythbuntu.
>

--
Mario Limonciello
<email address hidden>

Revision history for this message
laga (laga) wrote :

Dude!

Yes, it's working! mind you, this is a "sis" chipset. It most likely
wont work with Nvidia, but you knew that already.

Proof: (++) SIS(0): DPI set to (100, 100)

Afaik, this also works with "radeon".

Mario Limonciello schrieb:
> Dude,
>
> Does this work? You don't need to put in the DPI anywhere else like Display
> Size or anything like that when you do this? That'd be awesome!.
>
> On 10/10/07, Michael Haas <email address hidden> wrote:
>> Public bug reported:
>>
>> Title says it all.
>>
>> Fonts were unreadable on my TV because GDM was not set up to use -dpi
>> 100. Since we already fiddle with GDM config when we configure auto
>> login, it#d be cool to add -dpi 100 in there. I think that was also done
>> in ubuntu-mythtv-frontend.
>>
>> I've remedied this problem for now by adding this in gdm.conf-custom:
>> [server-Standard]
>> name=Standard server
>> command=/usr/bin/X -br -audit 0 -dpi 100
>> flexible=true
>>
>> ** Affects: mythbuntu
>> Importance: Undecided
>> Status: New
>>
>> --
>> -dpi 100 missing from X command line in gdm in Beta 1
>> https://bugs.launchpad.net/bugs/151310
>> You received this bug notification because you are a member of
>> Mythbuntu, which is the bug contact for Mythbuntu.
>>
>
>

Revision history for this message
Mario Limonciello (superm1) wrote :

I'll perform some mild experiments later this evening when I get home trying
this with a few different drivers.

On 10/10/07, Michael Haas <email address hidden> wrote:
>
> Dude!
>
> Yes, it's working! mind you, this is a "sis" chipset. It most likely
> wont work with Nvidia, but you knew that already.
>
> Proof: (++) SIS(0): DPI set to (100, 100)
>
> Afaik, this also works with "radeon".
>
> Mario Limonciello schrieb:
> > Dude,
> >
> > Does this work? You don't need to put in the DPI anywhere else like
> Display
> > Size or anything like that when you do this? That'd be awesome!.
> >
> > On 10/10/07, Michael Haas <email address hidden> wrote:
> >> Public bug reported:
> >>
> >> Title says it all.
> >>
> >> Fonts were unreadable on my TV because GDM was not set up to use -dpi
> >> 100. Since we already fiddle with GDM config when we configure auto
> >> login, it#d be cool to add -dpi 100 in there. I think that was also
> done
> >> in ubuntu-mythtv-frontend.
> >>
> >> I've remedied this problem for now by adding this in gdm.conf-custom:
> >> [server-Standard]
> >> name=Standard server
> >> command=/usr/bin/X -br -audit 0 -dpi 100
> >> flexible=true
> >>
> >> ** Affects: mythbuntu
> >> Importance: Undecided
> >> Status: New
> >>
> >> --
> >> -dpi 100 missing from X command line in gdm in Beta 1
> >> https://bugs.launchpad.net/bugs/151310
> >> You received this bug notification because you are a member of
> >> Mythbuntu, which is the bug contact for Mythbuntu.
> >>
> >
> >
>
> --
> -dpi 100 missing from X command line in gdm in Beta 1
> https://bugs.launchpad.net/bugs/151310
> You received this bug notification because you are a member of
> Mythbuntu, which is the bug contact for Mythbuntu.
>

--
Mario Limonciello
<email address hidden>

Revision history for this message
laga (laga) wrote :

Mario Limonciello schrieb:
> I'll perform some mild experiments later this evening when I get home trying
> this with a few different drivers.

Even if it doesnt work on all cases, so what? Adding that to the X
command line can't hurt IMHO.

Revision history for this message
Mario Limonciello (superm1) wrote :

Well as exciting as having this may be, I really don't want to have to
invoke BulletProofX (which works now!) if not necessary.

On 10/10/07, Michael Haas <email address hidden> wrote:
>
> Mario Limonciello schrieb:
> > I'll perform some mild experiments later this evening when I get home
> trying
> > this with a few different drivers.
>
>
> Even if it doesnt work on all cases, so what? Adding that to the X
> command line can't hurt IMHO.
>
> --
> -dpi 100 missing from X command line in gdm in Beta 1
> https://bugs.launchpad.net/bugs/151310
> You received this bug notification because you are a member of
> Mythbuntu, which is the bug contact for Mythbuntu.
>

--
Mario Limonciello
<email address hidden>

Changed in mythbuntu:
assignee: nobody → superm1
importance: Undecided → High
status: New → Fix Committed
Changed in mythbuntu:
status: Fix Committed → Fix Released
Revision history for this message
Adrian Wilkins (adrian-wilkins) wrote : Re: -dpi 100 missing from X command line in gdm in Beta 1

Please undo this - this is not appropriate particularly for a MythTV oriented distro.

The particular problem :
 * some TV-out drivers (nvidia 96 series in particular) only output 4:3 pixel resolution
 * using the dpi arg forces square pixels

So now you cannot get proper output on a 16:9 TV displaying a 4:3 pixel resolution without forcing aspect ratio in MythTV, because the effects of DisplaySize are ignored.

Recommend this is removed and a decent DisplaySize is set.

Changed in mythbuntu:
status: Fix Released → New
Revision history for this message
Adrian Wilkins (adrian-wilkins) wrote :

Confirm that removing this fixed my aspect ratio back up, after much finagling with Xorg options and wondering why they didn't work.

Revision history for this message
Mario Limonciello (superm1) wrote :

We're not particularly worrying about the earlier nvidia series of drivers. It's more if "The Right Thing" is done for the later one and open source drivers.

For example on my TV set, if this setting *isnt* in place, the installer is not readable at all with the open source drivers because the fonts are set too small.

Revision history for this message
Adrian Wilkins (adrian-wilkins) wrote :

Would it be closer to the right thing to define a default value for DisplaySize that is more appropriate to televisions, or does that not have enough effect on DPI?

Revision history for this message
Mario Limonciello (superm1) wrote : Re: [Bug 151310] Re: -dpi 100 forces square pixels even on 16:9 display with 4:3 pixel resolution

Problem is that you don't know whether people are installing on TVs or
Monitors - and what aspect ratio will be used. I see that on
http://www.mythtv.org/wiki?title=Display_Size&diff=32674&oldid=22694 the
revision indicating that mythtv required 100x100 DPI to look right has been
removed by Sphery, so I'll be open to more proper (and complete solutions).

On Tue, Mar 10, 2009 at 09:51, Adrian Wilkins <email address hidden>wrote:

> Would it be closer to the right thing to define a default value for
> DisplaySize that is more appropriate to televisions, or does that not
> have enough effect on DPI?
>
> --
> -dpi 100 forces square pixels even on 16:9 display with 4:3 pixel
> resolution
> https://bugs.launchpad.net/bugs/151310
> You received this bug notification because you are a member of Mythbuntu
> Developers, which is subscribed to Mythbuntu.
>

--
Mario Limonciello
<email address hidden>

Revision history for this message
Adrian Wilkins (adrian-wilkins) wrote :

My perspective is that for your problem it's better to have fonts that are a little too large, than fonts that are too small ; you only need to be reading the text for long enough to set a displaysize that is correct. Mine is set to the literal size of my TV screen in millimetres as is expected by X. If the DisplaySize is set by default to a size that produces fonts that are either readable, or a little too large, that is better than fonts that you cannot read.

I can't recall now how much text-only UI (if any) the MythBuntu installer contains (a good testament to it's slickness). I alas, had to use a monitor to set up and hand-edit my xorg.conf to gain TV out, because X does not display on the TV by default (but the basic terminal mode does). If there is some text-ui setup, would that be a good place to accept a DisplaySize?

An alternate thought was to set -dpi 100 for setup and configure a DisplaySize, at which point the dpi argument could be removed.

Revision history for this message
Nick Fox (nickj-fox) wrote :

Will be testing this with the latest Karmic build and MythTV .22 to see if its been resolved along the way.

Changed in mythbuntu:
assignee: Mario Limonciello (superm1) → Nick Fox (nickj-fox)
Nick Fox (nickj-fox)
Changed in mythbuntu:
status: New → Triaged
Revision history for this message
Mario Limonciello (superm1) wrote :

This bug has been indirectly resolved during 9.10. There is no longer a special gdm-cdd.conf to contain this launch parameter, so DPI is determined by X on it's own now.

Changed in mythbuntu:
status: Triaged → Fix Released
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